We are in the process of sequencing exome DNA from astrocytomas developing in multiple genotypes, including those that have only been engineered to initiate cancer and those that have only an additional progression event engineered. The informatic assessment of these sequences are telling us what genes/pathways consitently change during the evolution of disease in each case. Thus far we have sequences tumors arising in mice that have only been initiated and several changes correspond to those detected in human GBM.